“The National Federation of Mining Cooperatives, or Fencomin, should come clean by handing over the people responsible of Vice Minister Illanes' assassination,” said Interior Minister Carlos Romero to private TV channel PAT.

Romero, as well as Mining Minister Cesar Navarro, have been called to appear at the country's Congress on Wednesday, reported the president of the National Assembly Alvaro Garcia Linera. They will have to answer questions from legislators about the conflict with miners during the plenary session.

Rodolfo Illanes, deputy minister of the interior, was killed on Aug. 25 after being taken hostage by protesting miners earlier in the day on the highway between La Paz and Oruro in an area called Panduro.

Prior to the kidnapping, two people had died in clashes between striking miners and police near Cochabamba. A third person was killed in similar clashes before Illanes was found dead.

According to officials, Illanes died of torture with blows to the head and body in an act carried out with “malice and premeditation.” His aide was also seriously injured, but his condition stabilized after being in intensive care, local media reported.

At least 100 miners were arrested on Aug. 26 in the wake of Illanes’ killing. The Public Prosecutor’s office formally accused six suspects the day after the arrests for the murder, including leader Carlos Mamani, president of the Fencomin national mining cooperative federation behind the protests.

According to a statement, Mamani is accused of “murder, aggravated robbery, criminal organization, unlawful possession and carrying of weapons, and attacks against members of state security.” The other five face charges as accomplices.

The strike was sparked by a new piece of legislation, known as Law 149, enacted on Aug. 19. The law preserves labor rights but challenges direct contracts between miner cooperatives and transnational mining giants, instead requiring state involvement.

Miners rejected the law, demanding the government loosen environmental standards and allow mining cooperatives to sign contracts with private companies directly to increase mining opportunities. The initial list of 10 demands increased to 24 during the course of the protests.

Fencomin was previously aligned with President Evo Morales’ left-wing Movement Toward Socialism party, also known as MAS, which came to power with support of key social movements, including miners and coca growers.